One million sardines lie dead in the harbour area of Redondo Beach in California, USA.
It's thought that the fish were trying to shelter from rough seas but they soon exhausted the water's oxygen supply.
So the cleanup begins! A lifeguard scoops up the dead fish.
Officials say they would "recycle" the fish carcasses into fertiliser.
A boy looks at the very unusual sight - so many fish!
Here's what the marina looks like with all the dead fish floating around the boats.